Structural and impedance spectroscopy of α-Mn2O3

Abstract

The polycrystalline sample of α-Mn2O3 has been synthesized through standard solid-state reaction method. The room temperature (RT) powder X-ray and neutron diffraction has been performed to understand its crystal structure. The X-ray and neutron diffraction data refined using Rietveld analysis which shows the single-phase of the prepared sample with orthorhombic structure (Pcab). The detailed ac electrical measurements were carried out using dielectric constant and impedance spectroscopy at different temperatures at wide frequency range (4 Hz-1 MHz). The temperature dependent dielectric results show sharp increase in dielectric constant near 240 K which can be seen as the frequency dependent peak in tanδ. The non-Debye type dielectric relaxation is observed at broad temperature near room temperature. The contributions of grain and grain boundaries are also explored using impedance spectroscopy.